The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventor, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
The Karman line, lying at an altitude of 100 km above the sea level of the Earth, commonly represents the perimeter between the Earth's atmosphere and outer space. Accordingly, the majority of academic views hold that the application for air law governing aircraft, flying against air on specific route, and for space law governing satellites, circulating in inertial circular motion, shall be distinguished by this measurement of 100 km altitude. In consequence, the area of an altitude of more than 100 km shall be deemed as space shared by the humankind, and shall be subject to the principles of space law. On the other hand, the altitude of less than 100 km taken from the sea level shall be subject to the rules of air law under national and international legal systems. Furthermore, under the air law, unmanned aircraft vehicles (UAVs) are not governed by national laws for its activities in: (1) the atmosphere of a maximum altitude of 100 km above the high seas; and (2) the space of a minimum altitude of 100 km above the sea level of the Earth.
Aircrafts usually effectuate communication by radio waves. By contrast, long-distance communication and transmission between a satellite and the ground is usually effectuated by microwaves. The main difference in frequency transmissions between radio waves and microwaves is that microwaves for use in a frequency transmission are directive and thus must be strictly fixed to a precise, position-corrected dish antenna to receive and transmit messages.
Electromagnetic waves include radio waves, microwaves, infrared, visible light, X-rays, and gamma-rays; et cetera, depending on their specific frequencies (or wavelengths). Radio waves, which have a frequency of 300 GHz or below and a wavelength of 1 mm or above, propagate through free space (including air and a vacuum). Microwaves have a frequency that ranges from 300 MHz to 300 GHz and a wavelength that ranges from 1 m to 1 mm. The microwaves have a higher frequency than that of the radio waves and are usually known as “super high frequency electromagnetic waves.” Conventional artificial radio waves are widely applicable to wireless communication, broadcast, radar, communication satellites, navigation systems, and computer networks. However, conventional multi-path communication systems include satellite communication systems and operate at a microwave wavelength.
Electromagnetic waves, such as radio waves and microwaves, are susceptible to attenuation/fading—fluctuations of strength of the electrical field of a signal received, as a result of interference with the signal in the course of its transmission for natural reasons (such as rainfall) or artificial reasons (such as multi-path radio waves). In the situation where aircraft or satellites undergo frequency signal attenuation/fading and thus affect message reception and transmission, the aircraft or satellites can still fetch signals again before communicating with a ground-based control station to restore a communication transmission function, because all their apparatuses are built-in with electronic devices, such as a radio frequency computation system and wireless network, each of which has a self-recovery function. By contrast, the conventional method involves directly transmitting messages from the ground to aircrafts, UAVs or satellites presently operating in the air or in outer space, but the transmission process is again inevitably confronted with attenuation of radio frequency and microwave frequency in the course of long-distance transmission from the ground to an aerial vehicle to the detriment of the aircraft's recovery communication function. To eliminate the attenuation/fading of radio frequency and microwave frequency in the course of transmission across the atmosphere for natural reasons and artificial reasons and to get in line with the frequency attenuation arising from the Earth's rotation and revolution, the prior art discloses effectuating long-distance radio frequency transmission by enhanced frequency output power not only at the expense of technical requirements and cost control, but also at the risk of increased human exposure to radiation. In this regard, the conventional method to overcome the aforesaid known drawbacks is provided by commanding the aircraft, UAVs or satellites to go home for a ground repair, or delaying transmission, or discarding the UAVs or satellites, thereby incurring costs in operations and producing space junk.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.